The circular fluidizing bed boiler with unique hydrodynamic characteristics and structure has advantages such as wide fuel adaptability, high combustion efficiency, efficient desulfurization, low nitrogen oxide emission, large load regulating range etc. However, most fluidizing beds subject to non-uniform airflow distribution, resulting in high power and energy consumption. One of the measures to change such poor situation is adopting reasonable design to improve the airflow distribution system.
The airflow distribution system is one of the core systems of circular fluidizing bed boiler, and therefore airflow distribution uniformity is the essential factor to ensure the normal operation of the whole system. Inferior airflow distribution may affect the boiler's general combustion condition adversely, even cause failure of fluidizing beds combustion. Therefore, it is of vital importance to maintain a reasonable and uniform airflow distribution, in order to ensure normal fluidization, stable combustion and safe operation of the circular fluidizing bed boiler.
An airflow distributing plate central airflow distributing device for circular fluidizing bed boiler and the methods thereof is disclosed in China Patent Application No. 201410819148.8. The device described in the invention comprises a primary hot air duct that is connected to an under-bed start-up burner. The under-bed start-up burner is connected to a water cooling air chamber. The water cooling air chamber is connected to an airflow distributing plate and the airflow distributing plate is connected to a furnace. However, the airflow distributing plate central airflow distributing device and the airflow distributing method of the circular fluidizing bed boiler disclosed in this patent is difficult to implement in practice, and therefore fails to realize the effect of uniform airflow distribution.
A fluidizing bed airflow distributing system is disclosed in China Patent No. 201520167916.6. The system comprises two air chambers that are provided on two sides of a furnace in parallel and supplied with airflow from a main air supply duct. Several air ducts are welded between the two air chambers to form air supply channel. The two air chambers supply the air ducts with airflow. Several duct heads are provided on each air duct and an air cap is provided on each duct head to form primary air bed. However, the fluidizing bed airflow distributing system described in this patent fails to achieve uniform airflow distribution.
Therefore, a circular fluidizing bed uniform airflow distributing system is urgently required in the art.